is_pod Class
The latest version of this topic can be found at is_pod Class.
Tests if type is POD.
Syntax
template <class Ty>
struct is_pod;
Parameters
Ty
The type to query.
Remarks
is_pod<Ty>::value is true if the type Ty is Plain Old Data (POD). Otherwise it is false.
Arithmetic types, enumeration types, pointer types, and pointer to member types are POD.
A cv-qualified version of a POD type is itself a POD type.
An array of POD is itself POD.
A struct or union, all of whose non-static data members are POD, is itself POD if it has:
No user-declared constructors.
No private or protected non-static data members.
No base classes.
No virtual functions.
No non-static data members of reference type.
No user-defined copy assignment operator.
No user-defined destructor.
Therefore, you can recursively build POD structs and arrays that contain POD structs and arrays.
Example
// std_tr1__type_traits__is_pod.cpp
// compile with: /EHsc
#include <type_traits>
#include <iostream>
struct trivial
{
int val;
};
struct throws
{
throws() throw(int)
{
}
throws(const throws&) throw(int)
{
}
throws& operator=(const throws&) throw(int)
{
}
int val;
};
int main()
{
std::cout << "is_pod<trivial> == " << std::boolalpha
<< std::is_pod<trivial>::value << std::endl;
std::cout << "is_pod<int> == " << std::boolalpha
<< std::is_pod<int>::value << std::endl;
std::cout << "is_pod<throws> == " << std::boolalpha
<< std::is_pod<throws>::value << std::endl;
return (0);
}
/* Output:
is_pod<trivial> == true
is_pod<int> == true
is_pod<throws> == false
*/
Requirements
Header: <type_traits>
Namespace: std